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利用67个样点数据,研究了青藏高原高寒草原生态系统土壤碳氮比的分布特征。结果表明:(1)在水平方向上,土壤碳氮比呈现出西北高、东南低的总体态势和斑块状交错分布的格局,碳氮比的高值区主要集中在藏北高原腹地和喜马拉雅山北麓湖盆区,不同草地型和不同自然地带土壤碳氮比差异显著;(2)土壤剖面自上而下,不同草地型碳氮比可分为低-高-低型、由高到低型、由低到高型、高-低-高-低型和高-低-高型等5个类型。表土层(0—20 cm)与底土层(30—40 cm)土壤碳氮比差异显著;(3)土壤碳氮比与与最冷月均气温、年均蒸发量、年均相对湿度和土壤全氮含量呈极显著正相关关系,而与年均日照时数、年均气温、速效钾含量呈极显著负相关关系,这些环境因素对土壤碳氮比影响从大到小的顺序是年均相对湿度>年均日照时数>最冷月均气温>年均气温>年均蒸发量>土壤全氮含量>土壤速效钾含量。
Using 67 sample data, the distribution characteristics of soil C and N in the alpine grassland ecosystem in the Qinghai-Tibet Plateau were studied. The results showed that: (1) In the horizontal direction, the soil C / N ratio presented a pattern of northwest high and southeast low overall distribution and patchy staggered distribution. The high value areas of C / N ratio mainly concentrated in the hinterland of the northern Tibet Plateau and the Himalayas There are significant differences in soil carbon and nitrogen ratio between different types of grasslands and different natural areas in the mountainous area; (2) From top to bottom, the C / N ratio of different grassland types can be divided into low-high-low type and high Low-type, from low to high-type, high-low-high-low and high-low-high-type five types. There was significant difference in soil C / N ratio between topsoil (0-20 cm) and bottom soil layer (30-40 cm); (3) Soil carbon to nitrogen ratio was positively correlated with the lowest mean monthly temperature, average annual evaporation, annual average relative humidity and soil Total nitrogen content showed a significant positive correlation, but with the annual average sunshine hours, annual average temperature, available potassium content was significantly negatively correlated, the impact of these environmental factors on soil carbon to nitrogen ratio in descending order is the average annual Relative humidity> average number of sunshine hours> coldest average temperature> annual average temperature> annual average evaporation> soil total nitrogen content> soil available potassium content.